When extracting spectral information from a radiation source, Fourier transform spectroscopy is often used. Currently, Fourier transform spectrometers only provide limited ranges of spatial frequencies in which their response (i.e., their ability to collect spectral data) is acceptable. For example, Fizeau Fourier transform spectrometers tend to exhibit poor responses in low and zero spatial frequencies. Various approaches to restoring the spectral data missing from the spatial frequencies in which a Fizeau Fourier transform spectrometer has a poor response include estimation based upon prior knowledge of the scene being imaged, or computationally intensive approximation using known image processing techniques. These approaches provide, at best, only approximations of the missing data.
Accordingly, there is a need for a method to restore the spectral data corresponding spatial frequencies in which a Fizeau Fourier transform spectrometer has a poor response. The present invention satisfies this need and provides other advantages as well.